template <class T>
 struct SbtNode
 {
     typedef SbtNode<T> Node;
     Node* lch;
     Node* rch;

     T val;
     int lSize;
     int rSize;

     SbtNode(const T& _val):
             lch(),rch(),val(_val),lSize(),rSize() {}
     void assign(const T& _val)
     {
         lch=rch=;
         val=_val;
         lSize=rSize=;
     }
 };

 template <class T,class Comp>
 struct SizeBlcTree
 {
     ,Left=,Right= };
     typedef SbtNode<T> Node;
     typedef SizeBlcTree<T,Comp> Sbt;

     Node* root;
     Comp cmp;

     SizeBlcTree():root() {}
     ~SizeBlcTree() { clear(); }

     void clear_aux(Node* _cur)
     {
         if(_cur->lch) clear_aux(_cur->lch);
         if(_cur->rch) clear_aux(_cur->rch);
         delete _cur;
     }

     void clear()
     {
         if(root) clear_aux(root);
         root=;
     }

     Node* lRotate(Node* _cur)
     {
         Node* next=_cur->rch;
         _cur->rch=next->lch;
         next->lch=_cur;

         _cur->rSize=next->lSize;
         next->lSize+=(_cur->lSize+);

         return next;
     }

     Node* rRotate(Node* _cur)
     {
         Node* next=_cur->lch;
         _cur->lch=next->rch;
         next->rch=_cur;

         _cur->lSize=next->rSize;
         next->rSize+=(_cur->rSize+);

         return next;
     }

     Node* insert_aux(const T& _val,Node* _cur)
     {
         if(!_cur) return new Node(_val);

         if(cmp(_val,_cur->val))
         {
             ++_cur->lSize;
             _cur->lch=insert_aux(_val,_cur->lch);
             if(_cur->lch->lSize > _cur->rSize) return rRotate(_cur);
             else if(_cur->lch->rSize > _cur->rSize)
             {
                 _cur->lch=lRotate(_cur->lch);
                 return rRotate(_cur);
             }
             else return _cur;
         }
         else
         {
             ++_cur->rSize;
             _cur->rch=insert_aux(_val,_cur->rch);
             if(_cur->rch->rSize > _cur->lSize) return lRotate(_cur);
             else if(_cur->rch->lSize > _cur->lSize)
             {
                 _cur->rch=rRotate(_cur->rch);
                 return lRotate(_cur);
             }
             else return _cur;
         }
     }

     Sbt& operator << (const T& _val)
     {
         root=insert_aux(_val,root);
         return *this;
     }

     Node* erase_aux(const T& _val,Node* _cur,bool& _found)
     {
         if(!_cur)
         {
             _found=false;
             ;
         }
         if(cmp(_val,_cur->val))
         {
             _cur->lch=erase_aux(_val,_cur->lch,_found);
             if(_found) --_cur->lSize;
             return _cur;
         }
         if(cmp(_cur->val,_val))
         {
             _cur->rch=erase_aux(_val,_cur->rch,_found);
             if(_found) --_cur->rSize;
             return _cur;
         }

         _found=true;
         ;
         ;
         ;
         Node* res;
         Node* &prev=res;

         switch(status)
         {
         :
             delete _cur;
             ;
         :
             res=_cur->lch;
             delete _cur;
             return res;
         :
             res=_cur->rch;
             delete _cur;
             return res;
         :
             prev=_cur;
             if(prev->rch->lch)
             {
                 --prev->rSize;
                 prev=prev->rch;

                 while(prev->lch->lch)
                 {
                     --prev->lSize;
                     prev=prev->lch;
                 }
                 _cur->val=prev->lch->val;
                 prev->lch=erase_aux(prev->lch->val,prev->lch,_found);
                 --prev->lSize;
             }
             else
             {
                 _cur->val=_cur->rch->val;
                 _cur->rch=erase_aux(_cur->rch->val,_cur->rch,_found);
                 --_cur->rSize;
             }
             return _cur;
         }
     }

     Sbt& operator >> (const T& _val)
     {
         bool found=false;
         root=erase_aux(_val,root,found);
         return *this;
     }

     int notMoreCount(const T& _val)
     {
         Node* cur=root;
         ;
         while(cur)
         {
             if(cmp(_val,cur->val)) cur=cur->lch;
             else
             {
                 res+=(cur->lSize+);
                 cur=cur->rch;
             }
         }
         return res;
     }

     int lessCount(const T& _val)
     {
         Node* cur=root;
         ;
         while(cur)
         {
             if(cmp(cur->val,_val))
             {
                 res+=(cur->lSize+);
                 cur=cur->rch;
             }
             else cur=cur->lch;
         }
         return res;
     }
 };

 ;
 ;
 ;
 ;

 #include <functional>
 #include <algorithm>

 int unOrd[bktCount*bktSize];

 using std::less;
 SizeBlcTree<int,less<int> > all;
 SizeBlcTree<int,less<int> > bucket[bktCount];
 int N,K;
 int cs;

 #include <cstdio>

 void init()
 {
     scanf("%d%d",&N,&K);
     ;i<N;i++)
     {
         scanf("%d",unOrd+i);
         all<<unOrd[i];
         bucket[i>>bktDigit] << unOrd[i];
     }
 }

 inline void enumerate(int _rL,int _rR,int _val,int& _less,int& _notMore)
 {
     for(int i=_rL;i<=_rR;i++) if(unOrd[i]<=_val)
     {
         _notMore++;
         if(unOrd[i]<_val) _less++;
     }
 }

 int getAns(int _rL,int _rR,int _k)
 {
     int bktL = _rL>>bktDigit;
     int bktR = _rR>>bktDigit;

     int prevVal;
     SbtNode<int> *cur=all.root;
     while(cur)
     {
         ;
         ;
         if(bktL==bktR) enumerate(_rL,_rR,cur->val,less,notMore);
         else
         {
             ;i<bktR;i++)
             {
                 notMore += bucket[i].notMoreCount(cur->val);
                 less += bucket[i].lessCount(cur->val);
             }
             enumerate(_rL,((bktL+)<<bktDigit)-,cur->val,less,notMore);
             enumerate(bktR<<bktDigit,_rR,cur->val,less,notMore);
         }
         if(less<_k && notMore>=_k) return cur->val;
         prevVal=cur->val;
         if(less>=_k) cur=cur->lch;
         else cur=cur->rch;
     }
     return prevVal;
 }

 void solve()
 {
     char cmd;
     do cmd=getchar(); while(cmd==' ' || cmd=='\n');
     if(cmd=='Q')
     {
         int rL,rR,k;
         scanf("%d%d%d",&rL,&rR,&k);
         printf(,rR-,k));
     }
     else
     {
         int pos,v;
         scanf("%d%d",&pos,&v);
         --pos;
         all<<v;
         bucket[pos>>bktDigit] >> unOrd[pos];
         bucket[pos>>bktDigit] << (unOrd[pos]=v) ;
     }
 }

 void reset()
 {
     all.clear();
     int used=N>>bktDigit;
     ;i<=used;i++) bucket[i].clear();
 }

 int main()
 {
     scanf("%d",&cs);
     while(cs--)
     {
         init();
         while(K--) solve();
         reset();
     }
     ;
 }